0
\$\begingroup\$

I want to buy this integrated circuit (IC) to charge li-po battery. TP4056 Type-C 1S 3.7V

enter image description here

It looks nice for charging but I am afraid of the overdischarge protection of this IC because in the schematic below it looks out pins and battery pins are shorted so that the battery will be used without any turning off (overdischarge protection) and it will demage my li-po battery. Where am I going wrong, am I seeing it wrong?

enter image description here

\$\endgroup\$
2
\$\begingroup\$

Am I seeing it wrong?

Yes you are. Indeed the OUT+ and B+ connections are shorted but are the B- and OUT- also shorted? No, when the MOSFETs in the FS8205A are off, the battery - connection is disconnected from OUT-

The TP4056 isn't doing the protection, the DW01A is taking care of that.

\$\endgroup\$
3
  • \$\begingroup\$ Can I ask a last question? Are there any minimum current limit for charging? Because I have change TP4056 ICs R3 resistor 1.2k to 10k so charging current fall to 100mA and now it is not charging 1800mAh lipo battery ( power-xtra.com/uploads/content/… ) \$\endgroup\$ – mehmet Oct 7 '20 at 6:52
  • \$\begingroup\$ What is the voltage across the battery? If it is 4.1 V or higher then the TP4056 stops charging. Making R3 = 10 k should not be any issue. \$\endgroup\$ – Bimpelrekkie Oct 7 '20 at 6:59
  • \$\begingroup\$ well you are right, After waiting about half hour it start to charge. at first amper was very low after half hour amper goes to 100mA. I think 10k resistor is not for me, I should decrease the R3. \$\endgroup\$ – mehmet Oct 7 '20 at 14:03
1
\$\begingroup\$

The DW01A chip constantly monitors the battery connected to B+ and B- ports. If the battery voltage is under a threshold then the chip will turn off the mosfets, so the connection between B- and Out- will cut, and the battery has no connection to charge circuitry(tp4056) or load (which are connected to Out+ and Out-). If battery condition (voltage and current) is ok then the chip will turn on the mofsets and connects B- to Out-.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.